TOPIC: Running A/C in cold weather

Can someone give me the reason why you can't run an A/C when it is below 60 deg.  I have talked to several HVAC techs and they said it wasn't a problem.  The other thing I wonder about is that with a heat pump, heating is similar to running A/C in reverse; you run the condenser when it is cold to make heat, what are the issues when you run the A/C in the cold.  I've always heard you're not supposed to do it, but I haven't heard exactly why?  Thanks

From what I understand on how a heat pump works, you're right it doesn't matter. I've heard both sides for A/C. I'm sure some of the guys here can comment.

Can someone give me the reason why you can't run an A/C when it is below 60 deg.  I have talked to several HVAC techs and they said it wasn't a problem.  The other thing I wonder about is that with a heat pump, heating is similar to running A/C in reverse; you run the condenser when it is cold to make heat, what are the issues when you run the A/C in the cold.  I've always heard you're not supposed to do it, but I haven't heard exactly why?  Thanks

A/C compressors have a oil reservoir that should not be too cold at start up or permanent damage may occur. The actual temp. you should cut off at is 65 deg. and that should be for at least 24 hrs. prior to the inspection. There are others that say 48 hrs. prior, but most are comfortable with 24.
There are compressors now that have a small reservoir heater (electric) onboard, this is difficult for you to see without taking the unit apart. DO NOT ASSUME that the unit you are looking at has one. That is probably why your HVAC friends are saying no problem, but that is irresponsible of them.
Compressors are expensive to replace if you break one, so err on the side of caution.

I should clarify that it is not an actual reservoir that the compressor has, but the oil in the refrigerant separates in lower temps. and lays in the compressor like a reservoir. This is an excerpt from an article that explains it.

Most manufacturers recommend that you need at least three consecutive days of temperatures above 65 degrees to start up your compressor in the springtime. Also, don't run your compressor if it is below 65 degrees as it can cause damage to the compressor. (Why would you need to anyway?) There must be power to your compressor for at least 3 hours before starting it. This allows an electric coil to warm the compressor, vaporizing the liquid refrigerant. Liquid refrigerant in an operating compressor will damage it.

I hope that clears it up.

Greg, If you really want to know why, give me a call.

I'm not going through all of this again. It is much too long.

It simply is not what a HI should be evaluating.
But if you want to know the "why", I'd be more than happy to talk with you about it.

Phone number is on my web site.

Greg, If you really want to know why, give me a call.

I'm not going through all of this again. It is much too long.

It simply is not what a HI should be evaluating.
But if you want to know the "why", I'd be more than happy to talk with you about it.

Phone number is on my web site.

Mr. Andersen, this is not the first time this has happened, but I sure hope it is the last. If you did not like, or disagree with the answer that I gave Greg, or anyone else for that fact, please discuss it. To post something such as you did on a public forum shows what a sanctimonius gas bag you can be.

If you do not feel as though as you need to take the time to discuss your answer, (since that is what MB's are for) please email or pm the other person instead of making yourself sound GREAT at the expense of others on a public forum.